I'm no expert, but looking at the armaments of the Bf 109G I was thinking it may be an oversimplified MK 108 cannon, but post #2524302 and post #3540664 have the same design, so the artists definitely had to get it from somewhere.
I'm no expert, but looking at the armaments of the Bf 109G I was thinking it may be an oversimplified MK 108 cannon, but post #2524302 and post #3540664 have the same design, so the artists definitely had to get it from somewhere.
In case you missed it, this is based on the OVA "Operation Victory Arrow" where Erica is using a me_262 here rather than her usual bf_109 while her sister Ursula is using he_162. It was also stated in the OVA the cannon is the 50mm Mk 214 cannon. (Note that Mk 214 and BK-5 are 2 different designs using the same cartridge, both planned for Me 262 A-1a/U4)